calcaneal tendon




delcros 6

Platelet-rich plasma (PRP) is widely used intra-articularly, usually coupled with hyaluronic acid.

  • Protocolization of its use is still a matter of debate, but is becoming more standardized thanks to the pooling and exchange of international experts.
  • The use of PRP in tendinopathy has produced good results in practice, but studies are not conclusive regarding its efficacy [...1].
  • Nevertheless, properly conducted studies are rare: more rigorous designs and standardized randomized controlled trials are needed to produce more reliable and accurate results.

The calcaneal tendon is often used as a model for PRP studies, as it is superficial and easy to access.

  • Chronic calcaneal tendinopathy is a frequent pathology that quickly becomes a daily nuisance.
  • It accounts for 6 to 18 % of runners' injuries [...2, 3].
  • Numerous intrinsic and extrinsic factors contribute to the development of calcaneal tendinopathy: overwork, physical training or unsuitable equipment, stiffness of the posterior chain, anatomical variability... creating repeated local microtrauma, which then leads to degenerative changes and, in extreme cases, partial or complete rupture of the calcaneal tendon [...4].

Management is not standardized, but is based on the following principles:

  • first-line conservative treatment with rehabilitation (progressive loading of the tendon, eccentric strengthening according to the Stanish protocol [5],
  • painkillers per os (non-steroidal anti-inflammatory drugs, corticosteroids),
  • correction of predisposing factors,
  • wearing of orthopedic inserts, etc...

Second line:

  • infiltrative treatment (hyaluronic acid, corticosteroids, botulinum toxin and PRP) [ ].6],
  • and surgery is reserved for cases of total rupture or failure of other therapies.

However, practices remain poorly defined and the pathology often evolves into chronicity [...6].

Figure 1. Suroachilean chain with bulky calcaneal tendon distally.

From a biological point of view, studies in vitro have shown that leukocyte-rich PRP increases cell proliferation, migration and collagen synthesis.

In addition, most studies in vivo indicate an increase in type I collagen content. The overall histological quality of the tendons was improved, with better biomechanical properties [7].

On the other hand, a study of the technical parameters influencing PRP quality, showed that clinical performance improved the more the PRP was produced in a tube containing an anticoagulant, centrifuged at low speed, with a low leukocyte count and no erythrocytes [8].

In a study comparing PRP with saline injection, IL-10 expression was increased, while IL-6 and PGE2 were reduced, suggesting anti-inflammatory activity in contact with the tendon [...].9].

On the surgical side, intra-operative injections of PRP for the treatment of acute total rupture of the Achilles tendon significantly improved ankle dorsiflexion angle, ankle dorsal extension strength, and

calf circumference compared with controls [ ].10].

Another approach is to combine PRP (RegenPRP®) with an autologous thrombin preparation (RegenATS®), thus forming a platelet gel, low in leukocytes, with the dual benefit of filling and prolonged release of growth factors.

This platelet gel can be applied both intraoperatively during tendon suturing, and as an intratendinous infiltration in tendinopathy (Figure 1 and Figure 2).

Despite this, the data from studies carried out to date show no overall superiority of intratendinous PRP infiltration over saline or subcutaneous dry-needling, or of the addition of PRP intraoperatively for calcaneal tendon ruptures.

Yet the results observed clinically by many colleagues are positive!

What about this "clinical" discrepancy? vs. study results"? Studies involving larger samples, with more rigorous designs and standardized protocols, are needed to draw reliable and accurate conclusions.

For this reason, knowing how to define the type of tendinopathy is important, since the choice of indication for PRP infiltration depends on it [...11Fissure tendinopathies, whether corporal or enthesis, seem to be the most responsive cases.

Doppler Power ultrasound would indicate a good response to PRP. The infiltrative procedure accompanied by needling seems interesting.

Lastly, advice inherent to the procedure and the pathology should be protocolized [...11]: rest time, rehabilitation...

Figure 1. Eccentric strengthening

Figure 1. Fissured corporal calcaneal tendinopathy (longitudinal and axial sections): Injection of RegenPRP® + RegenATS® into the corporal cavity, then RegenPRP ® around the perimeter. Dr P. Adam (Clinique Médipole Garonne).

These treatments need to be tailored to the stage of tendinopathy and the phenotype of the tendon involved, as well as to the patient's age and comorbidities.

Several points need to be studied: clinical and imaging diagnostic criteria for calcaneal tendinopathy must be universal to avoid heterogeneity of patients and therefore of studies, and PRP production methods must be unified [...11].

Intratendinous PRP infiltration is part of a genuine chain of care, which we must insist on, because we remain convinced of its benefits for the patient.


Figure 2. Ultrasound check at 4 weeks post-infiltration / Residual cleft. Dr P. Adam (Clinique Médipole Garonne)


  1. Arthur Vithran DT, Xie W, Opoku M, Essien AE, He M, Li Y. The Efficacy of Platelet-Rich Plasma Injection Therapy in the Treatment of Patients with Achilles Tendinopathy: A Systematic Review and Meta-Analysis. Journal of clinical medicine. 2023;12(3).
  2. de Jonge S, van den Berg C, de Vos RJ, van der Heide HJ, Weir A, Verhaar JA, et al. Incidence of midportion Achilles tendinopathy in the general population. Br J Sports Med. 2011;45(13):1026-8.
  3. Van Middelkoop M, Kolkman J, Van Ochten J, Bierma-Zeinstra SM, Koes Prevalence and incidence of lower extremity injuries in male marathon runners. Scand J Med Sci Sports. 2008;18(2):140-4.
  4. Lu H, Yang H, Shen H, Ye G, Lin The clinical effect of tendon repair for tendon spontaneous rupture after corticosteroid injection in hands: A retrospective observational study. Medicine. 2016;95(41):e5145.
  5. Alfredson H, Pietila T, Jonsson P, Lorentzon R. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. The American journal of sports medicine. 1998;26(3):360-6.
  6. Zhang YJ, Xu SZ, Gu PC, Du JY, Cai YZ, Zhang C, Lin XJ. Is Platelet-rich Plasma Injection Effective for Chronic Achilles Tendinopathy? A Meta-analysis. Clin Orthop Relat Res. 2018;476(8):1633-41.
  7. Liu X, Li Y, Shen L, Yan M. Leukocyte and Platelet-Rich Plasma (L-PRP) in Tendon Models: A Systematic Review and Meta-Analysis of in vivo/in vitro Studies. Evidence-based complementary and alternative medicine : eCAM. 2022;2022:5289145.
  8. Kaux JF, Emonds-Alt T. The use of platelet-rich plasma to treat chronic tendinopathies: A technical analysis. 2018;29(3):213-27.
  9. Darrieutort-Laffite C, Soslowsky LJ, Le Goff Molecular and Structural Effects of Percutaneous Interventions in Chronic Achilles Tendinopathy. International journal of molecular sciences. 2020;21(19).
  10. Wang C, Fan H, Li Y, Yun Z, Zhang Z, Zhu Q. Effectiveness of platelet-rich plasma injections for the treatment of acute Achilles tendon rupture: A systematic review and meta- analysis. 2021;100(41):e27526.
  11. Liu CJ, Yu KL, Bai JB, Tian DH, Liu Platelet-rich plasma injection for the treatment of chronic Achilles tendinopathy: A meta-analysis. Medicine. 2019;98(16):e1527

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